AN/SPY-1 Radar

The AN/SPY-l radar system is the primary air and surface radar
for the Aegis Combat System installed in the Ticonderoga (CG-47) and
Arleigh Burke (DDG-51)-class warships. It is a multi-function phased-array
radar capable of search, automatic detection, transition to track, tracking of
air and surface targets, and missile engagement support.

A conventional, mechanically-rotating radar "sees" a target when the radar beam strikes that target once during each 360 degree rotation of the antenna. A separate tracking radar is then required to engage each target. By contrast, the computer-controlled AN/SPY-1A Phased Array Radar of the AEGIS system brings these functions together within one system. The four fixed arrays of "SPY" send out beams of electromagnetic energy in all directions simultaneously, continuously providing a
search and tracking capability for hundreds of target at the same time.

STRENGTHS

ANSPY-1 multifunction, phased array, fire
control quality radar.

Very rapid transition from SPY-1 silent to
full radiate and full situational awareness.

Fast reaction, fully/semiautomatic combat
systems. Initial detection to first missile
movement in less than 10 sec.

Salvo rate of less than 2 sec per launcher
(CG-52 and above with MK 41 VLS)

The system is designed for blue water and littoral operations however AN/SPY-1 configuration must be modified to look above the terrain to avoid causing excessive false targets from land clutter. These configuration changes may increase ship susceptibility to low and fast targets.

Once a target is engaged and the initial salvo fired, WCS will not allow the target to be reengaged (second salvo) until a kill evaluation has been completed.

AN/SPY-1 antenna height is lower than the AN/SPS-49 radar system resulting in reduced radar horizon.

DDG-51 Class are not equipped with a AN/SPS-49 radar (no secondary air
search radar)

Must hold an AN/SPY-1 track. Cannot engage on a remote or AN/SPS-49 track
unless equipped with CEC.

The SPY-1 radar program began in the early 1970s as part of the AEGIS weapon system development and acquisition process. Three versions of the radar have been delivered.

The first radar of the SPY-1 series, SPY-1A, is installed in the First AEGIS Cruiser, USS TICONDEROGA (CG 47), and subsequent ships until USS
PHILIPPINE SEA (CG 58).

As technology improved, the development program fielded a new version of SPY-1. This new radar is the SPY-1B
and, with its upgrade the SPY-1B(V), was built into USS PRINCETON (CG-59) and the remaining AEGIS cruisers. CG-59 through CG-73 are equipped with the the SPY-1B.

USS ARLEIGH BURKE (DDG 51) class ships, AEGIS destroyers, received the SPY-1D, the latest generation of the SPY-1 family. SPY-1D is a variant of the SPY-1B radar system on later TICONDEROGA (CG-47) class cruisers, tailored for a destroyer-sized ship. Significant funding is being allocated by the US Navy to upgrade or modify existing SPY-1D Aegis systems aboard the US Navy's CG-47 guided missile cruisers and DDG-51 destroyers to accomplish the TBMD function to meet US Navy requirements. These upgrades to the Aegis system consist of improved or new missiles, improved and new radars, and significant modifications to the software. SPY-1D is the only radar being considered by the US Navy today for upgrade to accommodate a TBMD capability.

The SPY-1F maintains the power and advanced capabilities of the AEGIS system found on guided-missile cruisers and destroyers, but its size has been scaled back to fit on smaller ships. Spain's F-100 program was the first application of the SPY-1F AEGIS system for frigates, which are smaller than the large guided-missile cruisers and destroyers that were previusly the only vessels with AEGIS systems. By virtue of its size, SPY-1D is a more powerful radar and, consequently, has increased range, but both the SPY-1D and the SPY1-F have air defense and ship self-defense capabilities. The SPY-1F, on the other hand, has not been designed to provide TBMD capability through software and hardware modifications.

The SPY-1D(V) radar upgrade is the newest improvement to the SPY-1D. The SPY-lD(
V) littoral radar upgrade will supersede the SPY-1D in new-construction ships beginning in FY 1998, and will deploy in DDG 51 Flight IIA ships starting in approximately 2003. The third variant of this radar, known as the Littoral Warfare Radar, will improve the radar's capability against low-altitude, reduced radar cross-section targets in heavy clutter environments and in the presence of intense electronic countermeasures. The SPY-1D radar system is the multi-function, phased-array, three-dimensional (range, altitude, and bearing) radar which conducts search, automatic detection, and tracking of air and surface targets. The SPY-1D also provides mid-course guidance for the SM-2 missile, and has also demonstrated a capability to track theater ballistic missiles. The AN/SPY-1D(V), under development for installation in some Flight IIA ships, is an improved
system with better performance against targets in clutter, additional moving target indicator (MTI) waveforms, and greater ability to counter deceptive Electronic Attack measures.

In May 1996, the Commander, Operational Test and Evaluation Force conducted the initial operational test of the SPY-1D(V) radar upgrade at the Moorestown site. The challenge of testing a naval radar in a ground environment was enormous. The Site lacked dynamic sea clutter, oceanic atmospheric anomalies, and very low flying targets. These limitations of the land-based Site were overcome by the extensive use of models and simulations. These models and simulations replicated the at-sea operating environment, providing simulated sea clutter, atmospherics, targets, and electronic jamming. All the models and simulations were accredited for use in this test after surviving a rigorous
validation procedure to determine their suitability. After a successful operational test, the SPY-1D(V) was approved for limited rate inital production by the Assistant Secretary of the Navy (Research, Development, and Acquisition) in December 1996.

Current funding completes the development of an upgrade to the current AN/SPY-1D radar, Engineering Development Model 4B (EDM-4B), to enhance its capability against low cross section sea skimming targets in increasingly more severe electronic
countermeasures and in near-land clutter environments. The changes are in the transmitter, signal processor, and radar control computer program. for the ARLEIGH BURKE (DDG 51) class ships Two new efforts will start in FY 1999. First, support for a Ballistic Missile Defense Organization (BMDO) Program which is developing a common, backfittable theater-wide radar upgrade signal processor to provide affordable theater-wide exoatmospheric discrimination capability. Second, integration of the AN/SPQ-9B radar into the AEGIS Weapon System to improve capability against the advanced low-altitude threat.